Fatty acid elongases (ELOVLS) and developmental changes in Rhodnius prolixus

GONDIM, KATIA C.; MAJEROWICZ, DAVID; DULBECCO, ANDREA B.; CALDERÓN FERNÁNDEZ, GUSTAVO M.; JUAREZ M.PATRICIA

Natal

Congreso; 45ª Reunión Anual de la Sociedad Brasilera de Bioquímica y Biología Molecular; 2016

Sociedad Brasilera de Bioquímica y Biología Molecular

Introduction: The insect cuticle is covered by a mixture of hydrocarbons (HC) and other fatty acid-related components, with an essential role in insect physiology, survival and chemical communication. Fatty acids are elongated by elongases (ELOVLs) with different substrate specificity. In Rhodnius prolixus (Hemiptera:Reduviidae), a major vector of Chagas disease, no information is available on the ELOVL genes that regulate the chain length of their fatty acyl-CoA products, precursors to cuticle HCs. A variation in the relative amount of straight chain HC from C27 to C33 between nymph and adult stages was detected. Although little is known about hormonal regulation on cuticle lipid metabolism, alterations on HC production were reported after juvenile hormone biosynthesis suppression in other insect species. We hypothesize that hormonal changes during metamorphosis might regulate the expression of ELOVL genes, affecting the HC pattern. Objectives: Identify the ELOVL genes in R. prolixus and analyze ELOVL gene expression during metamorphosis to adult stage. Methods and materials: Contig sequences of the R. prolixus genome were obtained from VectorBase. Gene identification was made using the software FAT with the consensus sequence of various domains from the Pfam database. To analyze gene homologies, protein sequences were aligned using ClustalW2.0, and dendrograms were constructed using the maximum likelihood method in MEGA6.0 software. The expression of ELOVL genes between IV-stage nymphs and adults was compared by quantitative PCR using specific primers based on the identified sequences. Results and Discussion: Several ELOVL genes have been reported in insect genomes, although their functions remain mostly unknown. Nine ELOVL genes were identified, showing high sequence homology with other insect ELOVLs. The analysis of the effect of developmental changes on their expression will be discussed with special emphasis in those genes responsible for the formation of very long chain fatty acids precursors to major HCs in R. prolixus.